There is a power supply unit known in the art. Such a power supply unit generally includes a snubber circuit and a diode. The snubber circuit includes a first winding of a regenerating transformer and a capacitor connected in series with the first winding. The diode feeds back an inductive voltage of a second winding of the regenerating transformer of the snubber circuit to a direct current power source.
There is another power supply unit known in the art. Such a power supply unit generally includes a winding which is coupled to a reactor of a snubber circuit, and a circuit which rectifies and smoothes an inductive voltage of the winding. Since the circuit feeds a part of energy which is collected in the snubber circuit to a load circuit, the power supply unit reduces a current which is flowing into a switching element.
According to the power supply unit which feeds back the inductive voltage of the second winding of the regenerating transformer of the snubber circuit to the direct current power source, power which is fed back to the direct current power source is resupplied to a secondary side circuit via a transformer. Accordingly, a part of the power which is fed back to the direct current power source is consumed in the transformer as surge energy. Thus, electrical consumption of the power supply unit is increased.
According to the power supply unit which includes the circuit that rectifies and smoothes the inductive voltage of the winding, only a positive component of the inductive voltage is supplied to the load circuit. Thus, a regeneration rate of the power supply unit is reduced.